Does the enabling of the /WAIT signal slowdown the V9958?

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Par msxegor

Master (183)

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30-12-2010, 15:54

Of course I will be happy if you send me a pair of 8s180's Smile
CSIO seems ideal for SD interface, however i doubt that it works well with DMA since its shifter is unbuffered. Need to read z180 datasheet.
As for Z280, will try to assemble a basic board tomorrow: it's just two chips and a couple of wire Smile

Par Leo

Paragon (1236)

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30-12-2010, 16:59

no prob mail me your postal address, yes i had thought also at that board for z280 , but i am afraid it will not work .
tomorrow il will try to do a z8s180 todil 40 adapter , i have a question : we can replace z80 with z180 just like this ( apart from plcc/dil convertion ) no need for extra chip ?i am 99% sure but i have never done it for real . i am planning to use regular 3.58Mhz clock, just toavoid confusion.

Par Leo

Paragon (1236)

Portrait de Leo

30-12-2010, 17:27

here is the pic of th z280 little board i had done this summer but nerver tried to solder .... single sided...
iledefra01.free.fr/msx/D20_0141.JPG

Par msxegor

Master (183)

Portrait de msxegor

31-12-2010, 12:09

About connecting Z180: you connect all similar signals 1:1, clock goes to EXTAL pin, extra INT pins should be tied high. This setup works ok. CPU boots at half the clock speed, you should switch to X1 clock option writing to internal Z8s180 port. I can send you schematic for the accelerator board

Par Leo

Paragon (1236)

Portrait de Leo

14-01-2011, 19:00

the Z80 replacement by Z180 finally worked out on SONY HB500 MSX2 , but not in SONY HB75B , it looks a bit slower , i guess it is due to 3 wait states by default + clock divide / 2 .
i should do some outs to set them correctly. but i am happy yet !
the clock is 3.5MHz , though the chip can go up to 33MHz , i may set it to 7Mhz then , i wonder if it could gain speed with more 2 or 3 wait states at 14MHz ?

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